Second Missouri Compromise

The Second Missouri Compromise, enacted in 1821, was a legislative measure that allowed Missouri to be admitted to the United States as the 24th state. This agreement was crucial in addressing a new crisis that arose after the initial Missouri Compromise of 1820. The earlier compromise had admitted Missouri as a slave state and Maine as a free state, while also banning slavery in the Louisiana Purchase territory north of latitude 36°30′.

The Second Missouri Compromise was necessary because Missouri's drafted constitution included a clause that could be interpreted to exclude free Black citizens from the state. To resolve this, Congress stipulated that Missouri could only be admitted if it agreed that this exclusionary clause would not infringe upon the rights of U.S. citizens. Missouri agreed, and was admitted as a slave state, while Maine had been admitted as a free state the previous year. This compromise temporarily eased sectional tensions over slavery but foreshadowed the deeper conflicts that would eventually lead to the American Civil War.12